You can catch walleye all summer long in US waters, you don't need to go to Canada. Charters go there in the summer because the fishing can be better and they have paying clients. Throughout summer walleye spread out and generally stay in deeper clearer water. A walleye can easily swim 15-20 miles in 24 hours. They move around looking for water conditions and forage they prefer. When they find it they generally stay there until it changes. Find water with the characteristics they like (a little cooler, deeper, clearer, higher O2, plenty of forage fish) and you will find walleye. A few of many spots to search? West of North Bass Island along the border a few miles and down to Rattlesnake Island. Around West Sister Island. The north and east side of Kelleys Island. Between Middle and North Bass Islands. Also try different times of day. Evening can be better than the morning. Try shallower depths early in the morning and late evening. Move until you find active fish, don’t stay in one spot too long that’s not producing. The walleye are often there, you just have to find active fish and then figure out how to catch them.